Query author contributions in Reactome
Reactome depends on collaboration between our curation team and outside experts to assemble and peer-review its pathway modules. The integration of ORCID within Reactome enables us to meet a key challenge with authoring, curating and reviewing biological information by incentivizing and crediting the external experts that contribute their expertise and time to the Reactome curation process. More information is available at ORCID and Reactome.
If you have an ORCID ID that is not listed on this page, please forward this information to us and we will update your Reactome pathway records.
Details on Person UniProt:P01906 HLA-DQA2
| Class:Id | ReferenceGeneProduct:56267 |
|---|---|
| _chainChangeLog | signal peptide:1-23 added on Sat February 7 2015;chain:24-255 added on Sat February 7 2015 |
| _displayName | UniProt:P01906 HLA-DQA2 |
| _timestamp | 2024-11-03 20:00:32 |
| chain | signal peptide:1-23 chain:24-255 |
| checksum | 85B13D9FDF2905FE |
| comment | FUNCTION Binds peptides derived from antigens that access the endocytic route of antigen presenting cells (APC) and presents them on the cell surface for recognition by the CD4 T-cells. The peptide binding cleft accommodates peptides of 10-30 residues. The peptides presented by MHC class II molecules are generated mostly by degradation of proteins that access the endocytic route, where they are processed by lysosomal proteases and other hydrolases. Exogenous antigens that have been endocytosed by the APC are thus readily available for presentation via MHC II molecules, and for this reason this antigen presentation pathway is usually referred to as exogenous. As membrane proteins on their way to degradation in lysosomes as part of their normal turn-over are also contained in the endosomal/lysosomal compartments, exogenous antigens must compete with those derived from endogenous components. Autophagy is also a source of endogenous peptides, autophagosomes constitutively fuse with MHC class II loading compartments. In addition to APCs, other cells of the gastrointestinal tract, such as epithelial cells, express MHC class II molecules and CD74 and act as APCs, which is an unusual trait of the GI tract. To produce a MHC class II molecule that presents an antigen, three MHC class II molecules (heterodimers of an alpha and a beta chain) associate with a CD74 trimer in the ER to form a heterononamer. Soon after the entry of this complex into the endosomal/lysosomal system where antigen processing occurs, CD74 undergoes a sequential degradation by various proteases, including CTSS and CTSL, leaving a small fragment termed CLIP (class-II-associated invariant chain peptide). The removal of CLIP is facilitated by HLA-DM via direct binding to the alpha-beta-CLIP complex so that CLIP is released. HLA-DM stabilizes MHC class II molecules until primary high affinity antigenic peptides are bound. The MHC II molecule bound to a peptide is then transported to the cell membrane surface. In B-cells, the interaction between HLA-DM and MHC class II molecules is regulated by HLA-DO. Primary dendritic cells (DCs) also to express HLA-DO. Lysosomal microenvironment has been implicated in the regulation of antigen loading into MHC II molecules, increased acidification produces increased proteolysis and efficient peptide loading.SUBUNIT Heterodimer of an alpha and a beta subunit; also referred as MHC class II molecule. Dimer formation with HLA-DQB2, but not with HLA-DQB1, is required for efficient exit from the endoplasmic reticulum (ER). In the ER, forms a heterononamer; 3 MHC class II molecules bind to a CD74 homotrimer (also known as invariant chain or HLA class II histocompatibility antigen gamma chain). In the endosomal/lysosomal system; CD74 undergoes sequential degradation by various proteases; leaving a small fragment termed CLIP on each MHC class II molecule. MHC class II molecule interacts with HLA_DM, and HLA_DO in B-cells, in order to release CLIP and facilitate the binding of antigenic peptides. Association with HLA-DMA also occurs in skin Langerhans cells, in post-Golgi compartments.INTERACTION The MHC class II complex transits through a number of intracellular compartments in the endocytic pathway until it reaches the cell membrane for antigen presentation.TISSUE SPECIFICITY Restricted to skin Langerhans cells, although some expression at low levels may occur at the surface of B lymphoblastoid cells.SIMILARITY Belongs to the MHC class II family. |
| description | recommendedName: HLA class II histocompatibility antigen, DQ alpha 2 chain alternativeName: DX alpha chain alternativeName: HLA class II histocompatibility antigen, DQ(6) alpha chain alternativeName: HLA-DQA1 alternativeName: MHC class II DQA2 |
| geneName | HLA-DQA2 HLA-DXA |
| identifier | P01906 |
| isSequenceChanged | FALSE |
| keyword | Adaptive immunity Cell membrane Disulfide bond Endoplasmic reticulum Endosome Glycoprotein Golgi apparatus Immunity Lysosome Membrane MHC II Proteomics identification Reference proteome Signal Transmembrane Transmembrane helix |
| modified | [InstanceEdit:84067] Schmidt, EE, 2003-12-18 04:29:09 [InstanceEdit:143527] Schmidt, EE, 2004-11-12 07:45:10 [InstanceEdit:217385] Schmidt, EE, 2008-03-27 06:23:53 [InstanceEdit:354386] Schmidt, EE, 2008-06-18 04:45:12 [InstanceEdit:384350] Kanapin, AA, 2008-11-26 14:00:39 [InstanceEdit:392885] Kanapin, AA, 2009-03-09 12:07:18 [InstanceEdit:400710] Schmidt, EE, 2009-03-25 05:33:35 [InstanceEdit:423310] Kanapin, AA [InstanceEdit:435478] Kanapin, AA [InstanceEdit:435871] Kanapin, AA [InstanceEdit:447347] Kanapin, AA [InstanceEdit:525883] Kanapin, AA [InstanceEdit:613449] Kanapin, AA [InstanceEdit:797602] Kanapin, AA [InstanceEdit:937368] Yung, CK [InstanceEdit:1042053] Yung, CK [InstanceEdit:1220657] Yung, CK [InstanceEdit:1300696] Yung, CK [InstanceEdit:1301627] Yung, CK [InstanceEdit:1551960] Weiser, JD [InstanceEdit:1995863] Weiser, JD [InstanceEdit:2132304] Weiser, JD [InstanceEdit:2265580] Weiser, JD [InstanceEdit:2587579] Weiser, JD [InstanceEdit:4341137] Weiser, JD [InstanceEdit:5083144] Weiser, JD [InstanceEdit:5433710] Weiser, JD [InstanceEdit:5618415] Weiser, JD [InstanceEdit:5634237] Weiser, JD [InstanceEdit:5673015] Weiser, JD [InstanceEdit:8987656] Weiser, JD [InstanceEdit:9037114] Weiser, JD [InstanceEdit:9637257] Weiser, JD [InstanceEdit:9657908] Weiser, JD [InstanceEdit:9676415] Weiser, JD [InstanceEdit:9715482] Weiser, JD [InstanceEdit:9852000] Weiser, Joel, 2023-11-03 [InstanceEdit:9926675] Weiser, Joel, 2024-11-03 |
| name | HLA-DQA2 |
| referenceDatabase | [ReferenceDatabase:2] UniProt |
| referenceGene | [ReferenceDNASequence:8987785] ENSEMBL:ENSG00000237541 HLA-DQA2 [Homo sapiens] |
| secondaryIdentifier | DQA2_HUMAN A2BF37 B0V0E7 O19789 Q5SQ94 Q5SR04 |
| sequenceLength | 255 |
| species | [Species:48887] Homo sapiens |
| (referenceEntity) | [EntityWithAccessionedSequence:197576] HLA class II histocompatibility antigen, DQ [plasma membrane] [Homo sapiens] [EntityWithAccessionedSequence:2130298] HLA class II histocompatibility antigen, DQ [trans-Golgi network membrane] [Homo sapiens] [EntityWithAccessionedSequence:2130414] HLA class II histocompatibility antigen, DQ [clathrin-coated endocytic vesicle membrane] [Homo sapiens] [EntityWithAccessionedSequence:2130434] HLA class II histocompatibility antigen, DQ [lysosomal membrane] [Homo sapiens] [EntityWithAccessionedSequence:2130563] HLA class II histocompatibility antigen, DQ [endocytic vesicle membrane] [Homo sapiens] [EntityWithAccessionedSequence:2130581] HLA class II histocompatibility antigen, DQ [transport vesicle membrane] [Homo sapiens] [EntityWithAccessionedSequence:2130675] HLA class II histocompatibility antigen, DQ [ER to Golgi transport vesicle membrane] [Homo sapiens] [EntityWithAccessionedSequence:2130719] HLA class II histocompatibility antigen, DQ [lumenal side of endoplasmic reticulum membrane] [Homo sapiens] [EntityWithAccessionedSequence:2214366] HLA class II histocompatibility antigen, DQ [Golgi membrane] [Homo sapiens] |
| [Change default viewing format] | |
No pathways have been reviewed or authored by UniProt:P01906 HLA-DQA2 (56267)
